ReadWriteWeb's Klint Finley interviewed Bitcoin contributor Gavin Andresen about how the open source Bitcoin project works.
According to the Bitcoin Web site, "Bitcoin is a peer-to-peer digital currency. Peer-to-peer (P2P) means that there is no central authority to issue new money or keep track of transactions. Instead, these tasks are managed collectively by the nodes of the network."
"The really novel idea," Andresen said, "is a mechanism for preventing bitcoins from being spent more than once without relying on a central authority."
So while companies like Facebook and Twitter cling to old-fashioned centralized servers and data hoarding, open source projects like Bitcoin and Diaspora are pushing the boundaries of decentralized computing.